With continuous and rapid construction of information communication networks in China, the communication level of China has been greatly improved to provide reliable guarantee for information exchange of every walk of life. Among numerous communication services, teleconference, especially a video conference service has shown more and more a good growth momentum. A video conference is a multimedia communication method for conferencing through a communication network by using video technology and devices. A video conference system joins conference terminals of multiple locales in a conference through a Multipoint Control Unit (MCU) so as to implement communication among a plurality of conference terminals. During the video conference, representatives at two or more different locations may hear voices from each other and see images of each other, and may also simultaneously see a scene of a conference room of each other as well as an object, a picture, a table, a file and so on presented in the conference, thus “shortening” a distance between representatives and enhancing the effect of the conference so that everybody are just like participating in the conference in the same place, and working efficiency is improved significantly.
However, information insertion may be required during the conference in practical application of a teleconference system. For example, a certain conferee wants to insert a piece of audio or video information into the conference so that the audio or video information may be presented to other conferees, or the certain conferee who cannot attend the conference pre-records a speech video or audio and it is expected that a speech content is inserted and presented to other conferees during the conference. However, a current video system still cannot satisfy such a requirement, thus the effect of the conference is influenced.